Damage-prone regions in polymeric and composite materials are difficult to detect and even harder to mitigate. Damage is preceded by complex spatial and temporal changes in stress state, and it is therefore desirable to utilize these mechanical changes to activate - without human intervention - chemical changes that favorably alter materials properties where and when they are needed. Desirable materials properties brought about in response to high-stress conditions include: (1) signal generation to warn of ensuing failure, (2) molecular structure modification to slow the rate of damage and extend lifetime (e.g., stress-induced crosslinking), and (3) repair of damage to avoid catastrophic failure. To realize these functions, molecular mechanisms are needed in which a kinetic barrier can be surmounted by stress-induced activation of a mechanophore - the putitive mechanically active unit. An experimental approach to develop new mechanophores will be presented. Examples involving electrocyclic ring-openings and hemolytic bond cleavage will be presented.
BIOJeffrey Moore was born near Joliet, IL in 1962. He received his BS in chemistry (1984) from the University of Illinois, and his PhD in Material Science Engineering with Samuel Stupp (1989). Following a NSF postdoctoral fellowship at Caltech with Robert Grubbs and an Assistant Professor appointment at the University of Michigan in Ann Arbor, he returned in 1993 to the University of Illinois, where he is currently the Murchison-Mallory Professor of Chemistry and Material Science and Enigneering. His research focuses on molecular self-assembly, structure-controlled macromolecules and foldamers, stimuli-responsive materials, and self-healing polymers.